#include <bits/stdc++.h>
#define pb push_back
#define pf push_front
using namespace std;
#define F first
#define S second
typedef long long ll;
#define pii pair <int, int>
#define pll pair <ll, ll>
typedef long double ld;
const ll N = 1e5 + 100, M = 4096 + 10, len = 315, inf = 1e18;
const ll mod = 1e9 + 7;
ll um(ll a, ll b){
	return (1LL * a * b) % mod;
}
ll subr(ll a, ll b){
	return ((1LL * a - b) % mod + mod) % mod;
}
pll a[N];
int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);
	cout.tie(nullptr);
	ll n;
	cin >> n;
	for(ll i = 0; i < n; i++){
		cin >> a[i].F >> a[i].S;
	}
	if(n == 2){
		cout << -1;
		return 0;
	}
  return 0;
}